%0 Journal Article
%T The roles of glutamate dehydrogenase, glutamine synthetase and three forms of glutamate synthase on nitrogen assimilation in various organs of Pisum arvense L.
%A Genowefa Kubik-Dobosz
%J Acta Societatis Botanicorum Poloniae
%D 1991
%I Polish Botanical Society
%R 10.5586/asbp.1991.022
%X The activities of GDH, GS and three forms of GOGAT (NADH, NADPH or ferredoxin-dependent) were studied in the leaves, stems and roots of the Pisum arvense. GS and the individual forms of GOGAT dominated in the leaves of 7 day-old plants which were taking up NO3- or NH4+ ions, while NADH-GDH dominated in the roots of these plants. In comparison with HNO3- , NH4+ ions stimulated the activity of most of the enzymes of the GS/GOGAT and GDH pathways in stems and roots, while in and leaves this effect was age-dependent. The Fd-GOGAT located in leaves and stems was not regulated by NH4+ , which indicates that this enzyme is not likely to be directly involved in the assimilation of NH4+ ions that have been taken up. The obtained data indicate that at lower tissue NH4+ concentration a decisive role in nitrogen assimilation in leaves and stems is played by the GS/GOGAT pathway, while in the roots-by GDH and in less degree by GS, GOGAT. High amounts of accumulated NH4+ ions set off a detoxication mechanism which includes NADH-GDH, common to all tissues. Only in 7 day-old leaves did the detoxication of NH4+ take place with the involvement of NADH-GOGAT and NADPH-GOGAT.
%K assimilation of NH4+
%K glutamate dehydrogenese
%K glutamine synthetase
%K glutamate synthase
%U http://pbsociety.org.pl/journals/index.php/asbp/article/view/1211